1. Field of the Invention
The present invention relates to a surface mounting semiconductor device having a resin package. The present invention particularly relates to a semiconductor device provided with an electrode for external connection which does not include a bent portion. The present invention also relates to a lead frame used for making such a semiconductor device.
2. Description of the Related Art
JP-A-11-345917 discloses an example of prior-art semiconductor device. As shown in FIG. 10 of the accompanying drawings, the prior art semiconductor device (generally indicated by a reference sign B) includes a semiconductor chip 90, a first lead 91A and a second lead 91B. The chip 90 is mounted on the first lead 91A in electrical conduction therewith. The chip 90 is connected via a wire W to the second lead 91B. The semiconductor device B further includes a resin package 92 for sealing the chip 90 and the wire W.
As shown in FIG. 10, each of the first and the second leads 91A, 91B is partially covered with the package 92. Specifically, each lead 91A, 91B includes an upper horizontal portion 93, a lower horizontal portion 94, and a vertical portion 95 for connecting the two horizontal portions 93, 94 to each other. Among these portions, the upper horizontal portions 93 and the vertical portions 95 are covered with the package 92, whereas the lower horizontal portions 94 are located outside the package 92 to extend along the bottom surface 92e of the package 92. The leads 91A, 91B are formed by bending a metal lead frame.
The prior art semiconductor device B has the following problems. Firstly, the bending of the lead frame for providing the first lead 91A and the second lead 91B is troublesome, increasing the time and cost for making the semiconductor device. Secondly, the existence of the vertical portions 95 (having a length S) of the leads 91A, 91B tends to increase the height of the semiconductor device B, which is disadvantageous.